Oligomerization process

ABSTRACT

Novel heterogeneous, nickel-containing catalysts comprising A. A nickel carbonyl complex, and B. An acidic, solid, silica-based material are active in numerous reactive environments such as oligomerization, including homo- and co-dimerization, and polymerization of various olefins. In specific aspects, bis(triphenylphosphine) nickel dicarbonyl supported on an acidic, calcined, silicaalumina support containing a separate alumina phase, is active in, for instance, the oligomerization, particularly dimerization, of ethylene and propylene, the codimerization of a conjugated diene and an alpha-olefin and the polymerization of conjugated dienes.

United States Patent [191 Yoo [451 Sept. 23, 1975 1 OLIGOMERIZATIONPROCESS [75] Inventor: Jin Sun Yoo, South Holland, Ill.

[73] Assignee: Atlantic Richfield Company,

Philadelphia, Pa.

[22] Filed: Dec. 11, 1972 [21] Appl. No; 314,147

Related US. Application Data Primary ExaminerPaul M. Coughlan, Jr.Attorney, Agent, or FirmThomas J. Clough [5 7] ABSTRACT Novelheterogeneous, nickel-containing catalysts comprising A. A nickelcarbonyl complex, and

B. An acidic, solid, silica-based material are active [62] Division ofSer. No. 49,968, June 25, 1970, Pat. No.

in numerous reactive environments such as oligomerization, includinghomoand co-dimerization, and polymerization of various olefins, Inspecific aspects, bis(triphenylphosphine) nickel dicarbonyl supported onan acidic, calcined, silica-alumina support containing a separatealumina phase, is active in, for instance, the oligomerization,particularly dimerization, of ethylene and propylene, the codimerizationof a conjugated diene and an alpha-olefin and the polymerization ofconjugated dienes.

9 Claims, N0 Drawings OLIGOMERIZATION PROCESS tain nickel. complexes,with or without certain Lewis I acids as a component, have beendisclosed in the prior art as useful catalytic species for enhancing thecyclooligomerization of 1,3-butadiene. Also, unsupr ported, homogeneouscatalysts containing certain nickel complexes and Lewis acids have beenstudied regarding the oligomerization of olefins. The use of suchcatalysts in liquid form is noted in US. Pat. Nos. 3,243,468; 3,414,629and 3,468,921 and in the literature in a paper, G. Ham and A. Miyake,Chem. Ind. London, p. 921 (1967).

The heterogeneous catalysts of this invention, however, overcomenumerous disadvantages attendant the use of such prior art catalyticspeciesThe use of the solid catalysts of this invention, in, forexample, a fixed bed or ina slurry form, eliminates the necessity forthe separationof the soluble catalytic species from the reactionproducts and thus eliminates catalyst losses normally occurring duringsuch separations. Also, since the nickel carbonyl complex of thecatalyst herein is firmly fixed upon the acidic, solid, silica-basedsupport material, probably either through a coordination bond or throughan electrostatic ionic bond formedthrough an ion exchange mechanism, thecatalyst is remarkably stable and active for long periods of time.Furthermore, the level of catalytic activity exhibited by the solidcatalysts of this invention is normally substantially higher than in thecorresponding homogeneous catalysts; in fact, most of the nickelcarbonyl complexes useful herein exhibit very slight or no catalyticactivity whatsoever in the absence of the support material. Therefore,the acidic, solid, silica-based material useful herein functions notonly as a supportbut also as a cocatalyst. Also, the heterogeneouscatalysts of this invention are useful for selective oligomerization,particularly dimerization processes. I

The nickel complexes useful in the catalysts of this invention includeas an essential ingredient nickel car.- bonyl complexes of the formula:

(L)hd mNi(CO),, I wherein L is a tertiary, essentially hydrocarbylactionof a nickel source such as an inorganic saltwith carbon monoxide andoptionally and preferably a Group V-A element monodentate ligand in asuitable solvent, such as hydrocarbon solvents. Preferably,, the nickelcompounds of the above formula are then separated from the mixture andused themselves as the nickel complex. The reaction mixture, however,might be used; the use thereof provides for the in situ preparation ofthe nickel carbonyl compounds and simultaneous or subsequentimpregnation upon the acidic, solid, silica-based support'andcocatalytic material of this invention.

The tertiary, hydrocarbyl-substituted 'rnonodentate ligand of a GroupV-A element useful in this invention include those represented by theformula:

wherein Y is a Group V-A element, i.e. nitrogen, phosphorus, arsenic,antimony or bismuth, p IS 2 or 3, and R is a mono-or divalentessentially hydrocarbon moiety.Thus, these Group V-A ligands are amines,phoshexyl, decyl, octadecyl, phenyl, bipheny l, B-naphthyl, IB-naphthyl, phenanthryl, tolyl, xylyl, mesrtyl, duryl, cu-

menyl, benzyl, phenethyLcyclobutyl, cyclopentyl, cyclooctyl,3-methylcyclohexyl, butylene and hexylene. The preferred Group V-Aelement ligands for the nickel complexes of this invention are theterttary mono phosphines. Exemplary of these are tnrnethylphosphine,triethylphosphine, tripropylphosphrne, trioctylphosphine,tridecylphosphine, drmethylethylphosphine, triphenylphosphine,tri(o-tolyl)phosphm e, tricyclobutylphosphine, tricyclopentylphosphme,tnbenzylphosphine, diphenylbenzylphosphine and methyl butylenephosphine. The corresponding anunes, arsmes, stibines and bismuthinesare also useful. Amine complexes such as bis(pyridyl) nickel dicarbonylare also useful. The most advantageous nickel complexes have been foundto be those wherein both m and n are two such asbis(trihydrocarbylphosphine) nickel dicarbonyls, for example,bis(triphenylphosphme) nickel dicarbonyl. Also, nickel tetracarbonyl isuseful. I

The solid support of the catalyst of the present invention is an acidic,silica-based material, e.g., having a D substituted monodentate ligandof a Group V-A element and m is an integer value from 0 to 3, preferablyat least one, and n is an integer value of l to 4, the sum of m and nbeing 4. ln essence, the nickel atom in the above represented compoundshas at least one and up to and including four carbonyl groups associatedthrough a bond therewith. Thus, n plus the number of Group V-A elementatoms associated with the nickel is four. The preparation of complexescontaining the nickel carbonyl compounds representedby the above formulais well known in the art. Advantageously, however, the nickel complexmight be prepared by the re- L activity of at least about 20, preferablyat least about 30 when determined according to the method of Birkhimeret al., A Bench Scale Test method for Evaluating Cracking Catalysts,Proceedings of the Amencan Petroleum Institute, Division of Refining,Vol. 27 page (1947), and hereinafter referred to as Cat A. Thesilica-based support preferably has a substantial surface area asdetermined by the BET nitrogen absorption procedure (JACS, Vol. 60, pp.309 et seq.) (1938). The surface area of the support can be at leastabout 50 square meters'per gram, and 2such surface areas are often up toabout 500 or more m /gm., preferably about to 400 m /gm. It is preferredthat the catalyst support be relatively dry to avoid undue reaction withand loss of catalytic promoting materials. Thus, it is advantageous thatthe support be calcined,

e.g., at temperatures of about 600 to 1500F or more, to reduce the watercontent, but such calcination should not be so severe that the supportis no longer sufficiently catalytically-active.

The support component contains other materials in addition to silicawhich materials, when combined with silica, provide an acidic materialas in, for instance, the case of silica-alumina. Often these materialsare one or more oxides of the metals of Groups II, III and IV of thePeriodic Table. Examples of the composites contemplated herein under thegeneric designation of silicabased materials are often composedpredominantly of, or even to a major extent of, silica. These supportsinclude, for example, silica-alumina, silica-boria, silicazirconia,silica-magnesia, silica-alumina-zirconia, silica-alumina-thoria,silica-alumina-magnesia, and the like. The silica-based support cancontain amorphous or crystalline material such as a crystallinealuminosilicate, for instance, having pore openings in the 6 to 15Angstrom unit range. The support often contains silica and alumina andsuch supports, whether naturallyoccurring as in acid-treated clays, or asynthetic gel, will frequently contain about 10 to 60, preferably aboutto 45, weight percent alumina. In addition, such silica-alumina supportscan, and preferably do, contain a portion of the alumina as a separate,distinct phase.

A highly preferred catalyst support can be made by combining asilica-alumina hydrogel with a hydrous alumina with or without(preferably without) a crystalline alumino-silicate. An advantageoushydrous alumina component is, when analyzed by X-ray diffraction of drysamples, either one or a mixture of amorphous hydrous alumina and amonohydrate, e.g., boehmite, of less than about 50 A, preferably lessthan about 40 A, crystallite size as determined by half-widthmeasurements of the (0, 4, 1) X-ray diffraction line calculated by theDebye-Scherrer equation. The mixture of the catalyst precursorcomponents can be dried, e.g., at about 220 to 500F. to convert thesilica-alumina hydrogel to xerogel form. The dried material can then becalcined, e.g., at a temperature of about 700 to l500F., preferablyabout 800 to l400F., to provide the active catalyst support. Duringcalcination, the separate hydrous alumina phase of the mixture isconverted to a gamma form or other catalytically-active alumina.

In providing the preferred catalyst support precursor for drying, thecomponents can be combined in any suitable manner or order desired, andadvantageously each of the components is in the mixture in finelydividedform, preferably the particles are principally less than about 300 meshin size. The finely-divided material can have an average particle sizeof about 10 to 150 microns and can be used to make a catalyst of thisparticle size which can be employed in a fluidized bed type ofoperation. However, if desired, the mixture of catalyst supportcomponents can be placed in macrosized form, that is, made intoparticles as by'tabletting, extruding, etc., to sizes of the order ofabout l/64 inch to 8% inch or more in diameter and about l/32 inch to 1inch or more in length, before or after drying or calcination. Ifformation of the macrosized particles is subsequent to calcination andthe calcined particles have been contacted with water, the material canbe recalcined.

On a dry basis, the preferred supports of the catalysts of the presentinvention contain about 45 to 95weight percent of the amorphoussilica-alumina xerogel, about 5 to 55 weight percent of the separatelyadded alumina phase, and about 0 to 50 weight percent of the crystallinealuminosilicate, preferably the proportions of these ingredients areabout 75 to 90%, about ID to 25% and about 0 to respectively. Ifpresent, the crystalline aluminosilicate is usually at least about 1weight percent, preferably at least about 5 weight percent, based on thedried support. The alumina content from the silica-alumina xerogel andthe separate alumina phase is about 20 to 70 weight percent, preferablyabout to 60 weight percent, based on the dried support. Also, thecatalyst support generally contains less than about 1.5 weight percent,preferably less than about 0.5 weight percent, sodium.

The silica-alumina component of the precursor of the preferred catalystsupport of the present invention can be a silica-alumina hydrogel whichcontains about 55 to 90, preferably 65 to 75, weight percent silica andabout 10 to 45, preferably about 25 to 35, weight percent alumina, on adry basis. The silica-alumina can be naturally-occurring or can besynthetically prepared by any desired method and several procedures areknown in the art. For instance, an amorphous silica-alumina hydrogel canbe prepared by coprecipitation or sequential precipitation by eithercomponent being the initial material with at least the principal part ofthe silica or alumina being made in the presence of the other.Generally, the alumina is precipitated in the presence of a silica gel.It is preferred that the silica-alumina hydrogel be made by forming asilica hydrogel by precipitation from an alkali metal silicate solutionand an acid such as sulfuric acid. Then alum solution may be added tothe silica hydrogel slurry. The alumina is then precipitated by raisingthe pH into the alkaline range by the addition of an aqueous sodiumaluminate solution or by the addition of a base such as ammoniumhydroxide Other techniques for preparing the silica-alumina hydrogel arewell known in the art, and these techniques may be used in the practiceof the invention.

The alumina hydrogel which can be combined with the silica-alumina ismade separately from the silica.- alumina. The alumina hydrogel may beprepared, for example, by precipitation of alumina at alkaline pH bymixing alum with sodium aluminate in an aqueous solution or with a basesuch as soda ash, ammonia, etc. As noted above, the alumina hydrogel canbe in the form of amorphous hydrous alumina or alumina monohydrate,e.g., of up to about 50 A crystallite size as determined by X-raydiffraction analysis. The amorphous hydrous alumina generally containsas much combined water as does an alumina monohydrate. Mixtures of themonohydrate and amorphous forms of hydrous alumina are preferred andoften this phase is composed of at least about 25% of each of theseparate members.

In preparing the catalyst support, one may separately filter thesilica-alumina hydrogel and the hydrous alumina and intimately mix thesematerials, for instance, by colloidal milling. Although in thisparticular procedure a low sodium crystalline aluminosilicate can beadded after the milling, this ingredient can also be combined before thecolloidal milling operation. The mixture is dried, water washed toacceptable concentrations of, for instance, sodium, and redried in thepreferred procedure. The drying, especially the initial drying, isadvantageously effected by spray drying to give microspheres.

The crystalline aluminosilicate which can be present in'catalyst supportof the present invention, can have pore openings of 6 to 15 A indiameter, and preferably the pore openings have a diameter of 10 to 14A. Usually, with a given material, the pores are relatively uniform insize and often the crystalline aluminosilicate particles are primarilyless than about 15 microns in size, preferably less than about 10microns. In the crystalline aluminosilicate the silica-to-alumina moleratio is often greater than about 2:1 and is usually not above about12:1, preferably being about 4 to 6:1. The aluminosilicate may beavailable in the sodium form, and the sodium can be removed before orafter the crystalline aluminosilicate is added to the other catalystsupport ingredients.

It is preferred to exchange the sodium with ammonium ions, for instance,through contact with an aqueous solution of ammonium chloride or anotherwatersoluble ammonium compound. Subsequently, during drying and/orcalcination, the ammonium ion may break down to release ammonia andleave an acid site on the aluminosilicate. On a molar basis, theammonium or hydrogen ion is usually at least about 10% or even at leastabout 50%, based on the alumina content of the crystallinealuminosilicate. Suitable replacements for the sodium also include thepolyvalent metals of the periodic chart, including the Group ll-A andrare earth metals such as cerium, etc. The metals may be present alonewith the ammonium or hydrogen cations.

The catalysts of this invention contain a minor, catalytically-effectiveamount of nickel complex and a major amount of the support, e.g. fromabout 2 to 2000 parts by weight of acidic, solid, silica-based supportmaterialzl part by weight of nickel carbonyl complex. The preferredweight ratio of acidic, solid, silica-based material to nickel carbonylcomplex is from about 5 to 200:1.

The catalyst compositions of this invention may be prepared by mixingthe acidic, solid, silica-based material with a solution or suspensionof the isolated or in situ prepared nickel carbonyl complex in an inertorganic solvent at about room temperature or above, i.e., 60 to 300F. orhigher. Normally, mixture at the lower temperatures within the range issufficient to form an active catalyst species. The mixture of catalystcomponents is generally stirred vigorously under a nitrogen atmospherefor periods ranging from 5 minutes to a few hours during the preparationof the active heterogeneous catalysts of this invention. Preferably,however, only the nickel carbonyl compound itself is thus added to thesupport material.

The supported catalysts of this invention are active in thehomodimerization, codimerization, oligomerization, and polymerization ofolefinic compounds. For example, the catalysts of this invention areuseful in the oligomerization of ethylene and propylene to form a majorportion of the corresponding dimers and a minor portion of higheroligomerization products. Normally, the oligomerization reactions areaccomplished at mild conditions, e.g. in the temperature range of fromabout -30 to 300F. The preferred temperature range is from about 100 to200F. under pressures of up to about 2000 psig or greater. Pressures ofless than about 500 psig are normally used. The reaction times may rangefrom as little as a few minutes to about hours. Substantial reaction isnormally accomplished at from about 1 to 5 hours.

Moreover, the supported catalysts of this invention have been found tobe useful in the codimerization of 1,3-conjugated diolefins having, forinstance, 4 to about 12 carbon atoms. and alpha-olefins having from 2 to10 carbon atoms to form a major portion of codimerization product. Morespecifically, l,3-butadiene and its alkyl, aryl and halogen-substitutedderivatives such as isoprene, piperylene, 2-phenyl-l ,3-butadiene orchloroprene are codimerized with alpha-o lefins of the formula RCH CHwherein R is hydrogen or a hydrocarbyl group of 1 to about 8 carbonatoms, preferably lower alkyl, to form a major portion of varioushexadiene products. Generally, reaction conditions previously describedas useful regarding the oligomerization reactions are also useful in thecodimerization of 1,3- conjugated dienes and alpha-olefins.

The polymerization of the l,3-conjugated dienes, say of 4 to about 12carbon atoms, may also be accomplished using the catalysts of thisinvention under similar reaction conditions. The higher molecular weightportions of the products from the previously described codimerization ofconjugated dienes and an alphaolefin are thus probably predominantlyhomopolymers of the conjugated diene. These homopolymers are generallyviscous, liquid polymers of the previously described conjugated dienes,e.g. those of 4 to about 12 carbon atoms, such as l,3-butadiene.

The amount of catalyst composition useful in the reactions of thisinvention is that sufficient to effect the desired reaction of theolefin feed or feeds. Thus, the essential requirement is that acatalytically effective amount of the compositions of this invention bepresent in the reaction mixture. Normally, this amount ranges from about0.01 to 25 percent by weight based on the weight of the reactant orreactants or a weight hourly space velocity of about 0.5 to 15,preferably about 2 to 6.

The preparation of an acidic, silica-alumina support of this inventionis illustrated by Examples l to Ill. This support contains a separatealumina phase.

EXAMPLE I An alumina hydrogel is prepared as follows:

In a tank containing 5700 gallons of water at F. are dissolved 300 lbs.of soda ash. When the soda ash has been dissolved, 180 gallons of a 39%concentration aqueous sodium aluminate solution are pumped into the tankin about a l5-minute period. The contents of the tank are at about 84F.600 gallons of aqueous aluminum sulfate of 7.8% eoncentration, as A1 0are added to the admixture over an 80-minute period with water ofdilution in conjunction with, and in addition thereto, diluting thereaction mass at a rate of 25 gallons per minute.

The pH of the resulting aqueous reaction mass is adjusted to 8.0 withabout 75 gallons of 39% concentration aqueous sodium aluminate solutionwhich, while being added, is also diluted continuously with water at arate of 35 gallons per minute over a 7% minute addition period. Thecontents of the tank are heated to about F., and pumped to storage.

The precipitated, hydrated alumina is thereafter filtered on a large gelfilter. The filtered product is partially purified by a one-cycle,water-wash on the filter on which it is collected. This filter is astring vacuum type drum filter with a built-in water spray nozzledirected toward the filter drum. Material on the drum is contacted withwater as the drum rotates past the nozzle. After washing, the wetalumina hydrogel is stripped from the drum. This hydrogel analyzes about50% boehmite having a crystallite size of about 35 A, and 50% amorphoushydrous alumina as determined by X-ray diffraction on dried samples.

EXAMPLE 11 A silica-alumina hydrogei is prepared by the followingtechnique:

To a batch tank is added 4,275 gallons of water preheated to 90F, and865 gallons of sodium silicate solutions (28.8 weight percent SiO-40-415 Baume at 68F. and Na O:SiO ratio of 1:3.2) is added. The batch isstirred for five minutes. The concentration of the so dium silicate, asSiO- in the batch is 6.3 weight percent.

With the batch at 90F, 302 gallons of 34.5 weight percent sulfuric acidsolution at 182F. are added over a period of 45 minutes. The gel formsabout 35 minutes after acid solution is begun. Then the pH is adjustedto 8.0-8.5. The batch is agitated for ten minutes.

Then 715 gallons of alum (7.8 weight percent, as A1 is added to the gelover a period of about 36 minutes. The batch is agitated for anadditional five minutes whereupon 205 gallons of sodium aluminatesolution (24.4 weight percent as A1 0 diluted in 1080 gallons of wateris added over a period of 17 minutes. After all the sodium aluminate isadded, the pH is checked. It should be between 5.0 and 5.2. The aluminacontent of the silica-alumina hydrogel is 30-31%.

EXAMPLE Ill The silica-alumina nydrogel product of Example 11 and 1740gallons of the alumina hydrogel filter cake of Example i are mixedtogether for 1 hour. The finished batch has a pH of 5.5 to 5.6 and atemperature of about 110F. The aqueous gel mixture is then pumped to adewatering filter and the filter cake from said dewatering filter and aportion of aqueous gel are blended to give a gel slurry of about 14weight percent solids. A portion of this hydrogel mixture was slurried,as a thick, flowable paste, with a Lightnin stirrer fitted with acage-beater and a propeller, for about minutes to give a thoroughdispersion. The product was stirred one minute at 14,500 rpm, in aWaring Blender and dried in a laboratory spray-drier. The spray-driedmaterial was washed with water to acceptable impurity levels and driedat 230F. The washed and dried material analyzed 0.08% S0 and less thanppm Na 0. The dried material as such was used as the catalyst support,as were extruded forms thereof and tablets (pellets) having diameters ofabout A: inch and lengths of about 76 to 5: inch. Before use, thecatalyst support was calcined in a muffle furnace by raising thetemperature by 300? per hour until i350F. was reached. This temperaturewas then heid for three hours. The calcined particles had a surface areaof about 320 to 340square meters per gram.

Examples EV to XX illustrate the preparation of the catalystcompositions of this invention on the silicabased support and theutilization thereof in various reactive environments.

EXAMPLE EV Extrudate pellets 10.0 g) of Example 111 were added to ahomogeneous solution of 0.98 miliimole of bis(tr1- phenylphosphine)nickel dicarbonyl in 32 ml toluene. Brown pellets resulted after 1%hours. The liquid phase was removed from the brown pellets, and thepellets were washed with toluene a few times. The resulting supportedpellets were transferred to a 300 cc stainless steei autoclave equippedwith an air driven stirrer. Five runs described in Examples V to 1X weremade in series with this catalyst over a 36% hour period.

EXAMPLE V In the first run, propylene (67.6 g) was fed to the catalystin the reactor of Example 1V, and was allowed to react with vigorousagitation at 140l60F. over a minute period. During this period, thepressure of the system dropped from 240 to 100 psig. A clear reactionmixture was removed from the reactor. All products obtained in the workwere analyzed by means of GL- chromatography and hydrogenationtechniques. Products in this first run were found to be composed ofabout 15% 2,3-dimethylbutenes, about 53% 2- methylpentenes, about 16%n-hexenes and about 15% of high boiling products (mostly C -olefins).The overall conversion of the propylene feed was 87%.

EXAMPLE V1 The second run was started with the 2-hour aged catalyst.Propylene (62.4 g.) was allowed to react for minutes under similarreaction conditions. The product distribution obtained in the second runwas essentially the same as that in the previous run and the overallconversion was about 71%.

EXAMPLE V11 in the third run, a mixed feed of propylene and butene-1 wasintroduced slowly and continuously to the catalyst, which was aged undera mixed atmosphere of air and unreacted propylene for 4% hours. Themixed feed 1.40 ml) required 90 minutes for addition to the reactor,after which the reaction was discontinued. Analysis of the productshowed that the propylene was selectively oligomerized in a conversionof about 90% to about 1 1% 2,3-dimethylbutnes, about 60% 2-methylpentenes, about 21% n-hexenes and about 5% nonenes, and thatbutene-l was essentially unconverted. In other words, littlecodimerization between propylene and butene-l had taken place with thiscatalyst. Thus, propylene can be selectively dimerized from the mixtureof propylene and butene with the catalyst of this invention. Thecomposition of the mixed feed (propylene and butene-1) used is asfollows:

Component: C C C iC nC C l, C =2T; Weight 0.01, 0.15, 31.18, 0.33, 0.17,68.14, 0.01.

EXAMPLE V111 The fourth run was made with the 20-hour aged catalyst.Isobutylene (81 g) was allowed to react under 75-116 psig and 152F. fora 75 minute period. Only slight pressure drop was observed. It appearsthat this catalyst is not highly active toward dimerization ofisobutylene under the reaction conditions employed since only about 5.0grams of higher boiling product was formed; however, employment of moredrastic reaction conditions would be expected to improve thisdimerization.

EXAMPLE 1X 1n the fifth run, ethylene was allowed to react with the 26%hour aged catalyst under about 600 psig a nd at l40-l 50F. for a hourperiod. Ethylene was converted in 61% yield to about 10% isobutene, 66%nbutenes, 6% 2-methy1pentenes, 8% 3-methy1per1tenes, 9% n-hexenes and 4%3-methy1heptenes.

EXAMPLE X A catalyst was prepared from 0.98 millimole of bis-(triphenylphosphine) nickel dicarbonyl and 10.0 g pellets of Example 111in 25 ml toluene. The brown pellets isolated from the liquid phase weretransferred to a 300 cc stainless steel bomb. Reactions were allowed toproceed with periodic agitation. Four runs were made with this catalystover a 313% hour period. Both the first and second runs were made withpropylene underisimilar conditions. The product distributions obtainedin these runs are essentially the same. Details of these re.- sults arelisted in Table lA-B. The third run was made with the 261 hour agedcatalyst. Ethylene was reacted in 73% yield to about 61% n-butenes, 8%2- methylpentenes, 9% 3-methy1pentenes, 9% n-hexenes, and 10%3-methy1heptenes. The pressure of the reaction system was maintained at400-800 psig-without EXAMPLE x1" Extrudate pellets of Example 111 (5.0g) were. added to a homogeneous toluene solution of, bis(t ripheny1-phosphine) nickel dicarbonyl (0.99 millimole in 55,m1 toluene). Afterthese pellets were kept in the solution for about minutes,.propy1ene(140 ml) was added to i V the mixture of pellets and liquid. The systemwas alcolorless reaction mixture was removed from the autoclave reactor,leaving behind the pellets containing supported 'bis(triphenylphosphine)nickel dicarbonyl. .Propylene was converted in 54% yield to-about 14%2,3-dimethy1butenes, 52% 2-methy1pentenes, 17% n-- 10 hexenes and 18% C-C -o1efin products.

EXAMPLE X11 7 1n the second run using the catalyst of Example XIpropylene (72.8 g) was again fed to the catalyst pellets,

15 which were left and aged in the autoclave for 3 hours.

The reaction proceeded with vigorous agitation at 160-400 psig and120-l70F. for 1% hours. During this period, 26 .0 g of product wasobtained; the product was not analyzed. v k i EXAMPLE x111 A homogeneoussolution of 0.97 inillimoles of bis(triphenylphosphine) nickeldicarbonyl in 551ml toluene was prepared under a nitrogen atmosphere inan autoclave. Propylene (145 ml).was introduced to this solution.Notethat no support pellets were added. The resulting homogeneous liquidsystem was allowed to. react with vigorous stirring under 115-130 psigand l50l52F. over 'a llhour period. However, bis(tri- 30phenylphosphine) nickel dicarbonyl alone did not catalyzetheoligomerization of propylene, In short, no reactionoccurred in thissystem. Judging from the results obtained from this andthe previousexamples, it becomes obvious that the support. material of Example 111is an ,essential catalyst component as well as an effectivesupportingbase. 1

TABLE 15.

- Catalyst Component Reaction Conditions Example Run (;,P)- .Ni(CO)Solvent Support Aged .Prcssure Temperature No. No. m mole m1 toluene' g.Hour psig F. Reaction Period v 0.9s 10.0 100-240 140-160 min. V1 2150-220 140-168 min. 4 VII 4% -210 -160 90 min. V111 i 20 75'l 16 -15275 min. 1x 26% 100 v I 140-150 10 hr. 1 I 7 1st O.98 10.0 180-300 I160-150 4% hr.

2 d.- 242 1610-300 120-160 2 2 hr. X .3111 I 261 40-800 Not Recorded 5V2hr. 4th 312 45-110 120 4hr.

= v, U Toluene Xl 0.99 55 ml 5.0 2110-250 120445 1% hr. x 1 3 1610-400120-170 1%hr. 1 l vToluene x111* 0.97 55 1 7 115-310 -152 v 1 hr.

"Homogeneous; S ystem TABLE 13 Hydrogenation of Product 1 V l Total Con-11: 4 Exv idem Prodveran-1 1e Run Feed Ki uct sion Noi No. g 1C nC .C-,s 2.3DMC 2MC 3MC nc..- fied "3MC; nC, C wt.g 7?

v "c -621s i. i '1 52.119 "1555-444" 12.'21 59.9 88.6 \71 0762.4 v 54.252 16.15 2114' w- 12.45 44.0 70.5

I z, based v11 c r-c: 59.76 2- 20.56 4.11 I 4.86 241 on c.,= 816 q Y89.\7-

TABLE lB-Continued Hydrogenation of Product Totul (on- VIll iCfXlll 5.0g Product [X 9.78 66.13 0.114 1.57 7.88 9.34 1.04 3.50 0.59 33.7 61.3 X12.58 44.40 13.89 2.50 26.63 54.7 75.2 14.23 51.74 15.88' 1.47 16.7038.9 74.8 60.75 2.09 2.17 7.55 9.30 8.60 9.56 63.7 73.5

I 5.0 g Product X1 13.87 51.75 16.80 6.38 11.20 39.7 54.4 Xll ($70.226.0 g Product Xlll C No Reaction EXAMPLE XIV Both 1.83 millimoles ofbis(triphenylphosphine) nickel dicarbonyl and 4.0 g. extrudate pelletsof Example III were weighed into a 300 cc autoclave along with 50 ml.toluene. These components were stirred vigorously under a nitrogenatmosphere at 80120F. for minutes. Immediately after, 100 ml. butadienewas added to the system. The reactor was pressured at a constantethylene pressure, 750 psig. Reaction was continued at 160F. for afour-hour period. The product was analyzed by means of a gaschromatographic technique. Tables III and 1V list details of the resultsobtained in this run. About 47% of the product was composed of varioushexadiene products such as 1,4- trans-; 1,4-cis; 2-trans,4-trans-;2-cis- 4-transhexadiene. Besides hexadiene products, 3- methylheptadiene(a codimer of conjugated 2,4- hexadiene product and an additionalethylene molecule) and 4-vinyl-l-cyclohexene (a homodimer of butadiene)were also obtained along with a large portion of heavier molecularweight product (37%). Analysis of the heavy product was not attempted.2,4- I-Iexadienes are products resulting from the isomerization of theinitial 1,4-hexadiene products. These 2,4- hexadienes, conjugateddienes, tend to react with an additional ethylene molecule to produce 3-methylheptadiene.

EXAMPLE XV EXAMPLE XVI 1,3-Butadiene (100 ml.) was fed to a systemconsisting of 0.87 millimoles of bis(triphenylphosphine) nickeldicarbonyl and 10.0 g extrudate of Example III in 30 ml. toluene in a300 cc stainless steel bomb. Ethylene was fed to the reactor under 800psig and was rapidly absorbed when the bomb was submerged in an oil bathset at 150F. A clear colorless reaction mixture was removed from thereactor after the reaction had proceeded for 30 minutes. Products wereanalyzed by gas chromatography, as listed in Tables III and IV. Theproduct was composed of about 33% of hexadiene isomer products, 14%4-vinyl-1-cyclohexene, 46% of heavy product and a small amount of 3-methylpheptadiene (1.2%). The solid catalyst left inside of the bomb wassaved for two more consecutive runs.

In the second run, ml. of 1,3-butadiene was added to the solid catalystaged from the first run, followed immediately by addition of ethylene.The system was maintained under an 800 psig ethylene pressure at F. for2 hours. The product distribution obtained in this run was quite similarto that obtained in the first run. Due to the tendency of the catalystpellets to absorb some of the surrounding liquid, it was impossible todischarge the reaction liquid quantitatively from the reactor. Thus,carry-over from the preceding run(s) was unavoidable throughout theseconsecutive runs made with the solid catalyst pellets.

The third run was made with 115 ml. 1,3-butadiene under 800-240 psigethylene pressure at 144F. for a 1% hour period. Details of the run arelisted in Tables III and IV. It seems clear from the results obtained inthese three consecutive runs that the catalytic species was firmly heldon the support and that catalytic activity was still maintained at anequal level even after these consecutive runs over a 5% hour period.

Three separate runs were made in order to study the reaction ofbutadiene with the present catalyst systems. They are described inExamples XVII to XIX.

EXAMPLE XVII In Run A, 1.25 millimoles of bis(triphenylphosphine) nickeldicarbonyl was dissolved in 40 ml. toluene and introduced into a 300 ccstainless steel bomb. The butadiene substrate (100 ml.) was fed to thesolution, and the reactor was kept in an oil bath set at 162I 82F for 3%hours. During this period, the pressure of the reaction increased frompsig to 340 psig. No significant reaction was noticed in this systemwithout support material. It was shown by mass spectroscopic analysisthat a very limited amount of butadiene homodimer was present in thedischarged reaction mixture. It was also learned from related work thatbis(triphenylphosphine) nickel dicarbonyl solution in an inert solventwas inactive for the cross-dimerization of 1,3- butadiene and ethylenein the absence of the support material.

EXAMPLE XVIII Run B employed the catalyst system containing 0.85;

the whole bomb was submerged in an oil bath set at 1-58F. for aboutminutes. 1,3-Butadiene (110 ml.) was fed to the system, and allowed toreact for about an hour. A viscous liquid polymer of polybutadienehaving low molecular weight was obtained. The support material was thusan essential catalytic component in creation of an active catalyticspecies from bis(triphenylphosphine) nickel dicarbonyl for thepolymerization of 1,3-butadiene.

EXAMPLE XIX wherein L is a tertiary, hydrocarbyl-substituted monodentateligand of a Group VA element, m is an integer value from 1 'to 3 and nis an integer value of l to 3 the sum of m and n being 4; and

b. a major amount of an acidic, solid, silica-based support material asan essential catalyst component.

2. A process of claim 1 wherein the weight ratio of (b) to (a) is fromabout 2 to 2000zl.

3. A process of claim 1 wherein the nickel complex is a bis(tertiary,hydrocarbyl-substituted monophosphine) nickel dicarbonyl complex.

4. A process of claim 3 wherein each hydrocarbyl substituent of themonophosphine is a hydrocarbyl group of up to about 20 carbon atoms.

5. A process of claim 4 wherein each hydrocarbyl group is phenyl.

6. A process of claim 5 wherein the weight ratio of (b) to (a) is fromabout 5 to 200:1.

7. A process of claim 1 wherein the silica-based support material iscalcined and has a separate, additional alumina phase.

TABLE 11 Catalyst Composition Catalyst Reaction Conditions Example Run(P) Ni(CO). Support Solvent Aged Pressure Temperature Time No. No.m-'mo1es g. ml toluene hr. psig F. hr.

XIV 1.83 4.0 50 750 160 4 XV 0.85 4.5 800 ll612() l XVI 1st 0.87 10.0 30800 150 V:

2nd 0.87 10.0 /2 780 150 2 3rd 0.87 10.0 3 800-240 144 1% XVII 1.25 40340-180 162-182 3% XV111 0.85 10.0 30 205135 158 l XIX 1.13 1 4.5 4073-172 138-196 4 TABLE 111 Product Distribution Ex- Heaample Run FeedCi; Total Ci Un- \y Total No. No. g. 1.5 1,4t 1,4c 2t,4t 2c,4t 2c,4c g.wt. known 3MC 4VC 'C Prod. Prod.

wtf/z wt. (7( g XIV Cf +BD 62.7 2.1 30.6 12.5 2.6 2.4 0.4 8.3 46.9 5.11.5 5.6 37.2 17.8 XV 75.2 0.9 26.8 16.8 3.5 3.7 0.6 6.0 52.2 2.4 14.830.5 11.5 XVI 1st 62.7 0.1 15.6 12.0 1.7 2.4 0 2.5 33.0 7.5 1.2 4.0 45.67.6

3rd 72.1 18.9 13.1 1.4 1.7 0.3 3.8 35.4 0.8 18.9 44.8 10.8 XV11 BD 62.7no significant reaction. XV111 BD 72.1 small portion of poly BDobtained. XIX BD 62.7 white poly BD polymer.

It is claimed:

8. A process of claim 6 wherein the silica-based support material iscalcined, has a separate, additional alu- 55 mina phase and has asurface area of about 150 to 400 square meters per gram.

9. A process of claim 1 wherein the support is comprised of about to 95weight percent amorphous silica-alumina and about 5 to weight percent ofa separate alumina phase, the total alumina content of said supportbeing about 20 to 70 weight percent.

1. IN A PROCESS FOR THE OILGOMERIZATION OF ONE OR MORRE ALPHAMONOOLEFINS SELECTED FROM THE GROUP CONSISTING OF ETHLENE AND PROPYLENE TOFORM A MAJOR PORTION OF A DIAMER PRODUCT, THE IMPROVEMENT WHICHCOMPRISES CONDUCTING SAID OILOMERIZATION IN CONDUCT WITH A HETEROGENEOUSCATALYST COMPRISING: A. A MINOR, CATALYTICALLY EFFECTVE AMOUNT OF ANICKEL COMPLEX OF THE FORMULA
 2. A process of claim 1 wherein the weightratio of (b) to (a) is from about 2 to 2000:1.
 3. A process of claim 1wherein the nickel complex is a bis(tertiary, hydrocarbyl-substitutedmonophosphine) nickel dicarbonyl complex.
 4. A process of claim 3wherein each hydrocarbyl substituent of the monophosphine is ahydrocarbyl group of up to about 20 carbon atoms.
 5. A process of claim4 wherein each hydrocarbyl group is phenyl.
 6. A process of claim 5wherein the weight ratio of (b) to (a) is from about 5 to 200:1.
 7. Aprocess of claim 1 wherein the silica-based support material is calcinedand has A separate, additional alumina phase.
 8. A process of claim 6wherein the silica-based support material is calcined, has a separate,additional alumina phase and has a surface area of about 150 to 400square meters per gram.
 9. A process of claim 1 wherein the support iscomprised of about 45 to 95 weight percent amorphous silica-alumina andabout 5 to 55 weight percent of a separate alumina phase, the totalalumina content of said support being about 20 to 70 weight percent.